There are of course a great many heat exchangers manufactured and, more particularly if we consider the manufacture of the heat radiators for motor vehicles, the height of the heat exchangers, i.e. the length of the tubes connecting together the two end plates, vary greatly from one type to the other. It is a similar situation with respect to the length of the end plates and, also, but to a smaller extent, with the thickness of the heat exchangers as well as also the width of their end plates.